Detailed Product Description API Bentonite is used to increase viscosity and reduce fluidloss in waterbase drilling fluids. It is a costeffective means of achieving viscosity, fluidloss control and filtercake quality in freshwater and seawater muds. Description: Fan viscometer dial reading at 600r/min: 30 min. API. FL (ml/30min): 15.0 max. Yield point / plastic viscosity ratio: 3.0 max. Moisture percent: 10.0% wt max. Residue on US sieve no. 200: 4.0% wt max. Packing: Packed in PP-woven bags with inner layer of polyethylene film Net weight: 25kg, 50kg, 1000kgor 100lbs/bag Other packing and bag sizes are also available.